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61.
Kara Perlman 《家电科技》1998,(5)
为使连接器保持竞争力,工程人员们都在努力提高其使用简易程度和成本效益以及工效学.连接器仅在气密和阻漏方面优越是不够的.在今天市场上,作为连接器工业还必须具其它卓越性能. 相似文献
62.
Disassembly is a critical step to increase the value of end-of-life (EOL) products and to reduce the environmental footprint. Despite worldwide efforts, disassembly is still performed manually due to the uncertainty associated with the quality and the quantity of the returned EOL products. In this paper, a cognitive robotics based system is proposed to address this problem. The system is equipped with four cognitive functions: reasoning, execution monitoring, learning and revision. The proposed system is tested using LCD screens. The results show that the system is flexible enough to deal with any product models without prior information. 相似文献
63.
We present a computational recognition approach to convert network-like, image-based engineering diagrams into engineering models with which computations of interests, such as CAD modeling, simulation, information retrieval and semantic-aware editing, are enabled. The proposed approach is designed to work on diagrams produced using computer-aided drawing tools or hand sketches, and does not rely on temporal information for recognition. Our approach leverages a Convolutional Neural Network (CNN) as a trainable engineering symbol recognizer. The CNN is capable of learning the visual features of the defined symbol categories from a few user-supplied prototypical diagrams and a set of synthetically generated training samples. When deployed, the trained CNN is applied either to the entire input diagram using a multi-scale sliding window or, where applicable, to each isolated pixel cluster obtained through Connected Component Analysis (CCA). Then the connectivity between the detected symbols are analyzed to obtain an attributed graph representing the engineering model conveyed by the diagram. We evaluate the performance of the approach with benchmark datasets and demonstrate its utility in different application scenarios, including the construction and simulation of control system or mechanical vibratory system models from hand-sketched or camera-captured images, content-based image retrieval for resonant circuits and sematic-aware image editing for floor plans. 相似文献
64.
DuPaul George J.; Power Thomas J.; Anastopoulos Arthur D.; Reid Robert; McGoey Kara E.; Ikeda Martin J. 《Canadian Metallurgical Quarterly》1997,9(4):436
Behavior rating scales are a primary method for screening and identifying children with attention deficit hyperactivity disorder (ADHD). The factorial structure and normative data of a teacher rating scale containing the 18 symptoms of ADHD were examined in this study. Factor analyses and assessment of differences in ADHD ratings across sex, age, and ethnic group were conducted with 4,009 children and adolescents who attended kindergarten through 12th grade in 31 U.S. school districts. Two factors (inattention and hyperactivity-impulsivity) were derived, and normative data for a nationally representative sample were presented. Boys, younger children, and African Americans received higher ratings of ADHD symptoms. Limitations of this investigation and potential uses of this scale in clinical practice and research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
Serena Bisagni Benjamin Summers Selin Kara Rajni Hatti-Kaul Gideon Grogan Gashaw Mamo Frank Hollmann 《Topics in Catalysis》2014,57(5):366-375
Baeyer–Villiger monooxygenases (BVMOs) are valuable enzymes for specific oxyfunctionalization chemistry. They catalyze the oxidation of ketones to esters, but are also capable of oxidizing other chemical functions, namely aldehydes and heteroatoms such as sulfur, nitrogen, selenium and boron. The oxidation specificity and enantioselectivity of a newly characterized BVMO (BVMO4) from a strain of Dietzia towards sulfide- and aldehyde substrates have been studied. BVMO4 could react with sulfides containing an aromatic group. The presence of a substituent on the aromatic group was tolerated when they were in the meta- and para position and the oxidations yielded predominantly the (R)-sulfoxides. Similarly, BVMO4 displayed a higher activity for aldehydes containing a phenyl group, but long aliphatic aldehydes, namely octanal and decanal, were also accepted as substrate by this enzyme. The major oxidation products of the aldehyde substrates were the respective carboxylic acids in contrast to formate ester that was obtained in most of the previous reports. The Baeyer–Villiger oxidation of the substrate 2-phenylpropionaldehyde was studied in further detail and the corresponding acid product was obtained with good regio- and enantioselectivity. This is a unique feature for BVMO4 and is of great interest for further exploration of an alternative biocatalytic process. 相似文献
66.
Gina M. Canfield Jeffery Eichler Kara Griffith John D. Hearn 《Journal of Materials Science》2014,49(17):5922-5933
In this research effort, the role of calcium in geopolymers was investigated through a series of syntheses where a high-calcium fly ash was blended with a low-calcium fly ash. Increased calcium content led to accelerated set-up times, increased compressive strength, and increased product formation. Powder X-ray diffraction results showed the majority of that product to be geopolymer framework with only minor contributions from calcium silicate phases. Thermal analysis confirmed the absence of a calcium silicate hydrate phase. Analysis of fly ash dissolution showed that calcium aided in aluminosilicate dissolution and therefore the geopolymerization reaction. While aiding in this reaction, calcium became incorporated into the pore structure of the geopolymer as a counter-balancing cation, according to ion exchange experiments. Thus, geopolymer synthesis with increased calcium content through the use of a high-calcium fly ash under these experimental conditions produced a quick-setting, strong, calcium incorporated geopolymer material. 相似文献
67.
68.
Reuse of components is one of the most efficient strategies for product recovery, which requires reliable methods for assessing the quality and the remaining life of used components. A new methodology, presented in this paper, is based on the trend analysis of lifetime monitoring data. Data with similar trends were grouped and a number of analysis techniques such as Linear Multiple Regression, Dynamic Ordinary Kriging, Universal Kriging and Neural Networks were applied in order to find the most suitable methodology for each group. The methodology was validated by using lifetime monitoring data from a consumer product. 相似文献
69.
70.
Low density lipoprotein (LDL) has been found suitable as a targeting carrier for cytotoxic drugs. However, higher drug loading into LDL particles without disrupting their native integrity remains a major obstacle. The purpose of this study is to investigate the different physicochemical factors that may affect drug loading and to characterize LDL-drug conjugates. Doxorubicin (Dox) and 3', 5'-O-dipalmitoyl-5-iodo-2'-deoxyuridine (dpIUdR) were used as reference cytotoxic drugs. Drugs were loaded into LDL particles using the dry film method with or without surfactants, liposomal and the direct addition method. The effects of incubation temperature, time and stoichiometry of LDL-drug conjugates on drug loading were investigated. The LDL-drug conjugates were evaluated for their stability and characterized by differential scanning calorimetry (DSC), denatured gel (SDS-PAGE), and electron microscopy (EM). We have suitably incorporated 45+/-10 Dox and 150+/-25 dpIUdR molecules/LDL particle. A seven-fold increase in Dox incorporation was achieved with the liposomal preparation compared to the dry film method. A 4- to 6-h incubation at 37 degreesC was suitable to restore the native structure of LDL particles. No apo B fragmentation of LDL particles was noted on denatured gel. DSC studies showed no change in the Tm of the LDL and the LDL-drug conjugates. An increase in particle size of LDL-dpIUdR, not LDL-Dox was observed in EM compared to the native LDL which may be related to higher incorporation of dpIUdR. The results indicate that physicochemical factors significantly affect drug loading efficiency and may need to be considered to optimize drug incorporation into LDL particles. 相似文献